Ka대역의 이동성을 고려한 양방향 위성방송통신융합 채널 전송방식 연구

Abstract

In the beginning of satellite broadcasting systems, concatenate coding schemes are considered as being the best solution for powerful protection of digital information against nonlinear distortion and fading noise. However, the performance of concatenate coding scheme is away from Shannon’s limit. The emergence of the iteration decoding algorithms such as turbo codes and Low Density Parity Check (LDPC) codes has changed our view of the Shannon capacity, the capacity has become a practical benchmark for a coding system not only for power limited channels but also for bandwidth channels. Therefore, the high definition television (HDTV) satellite standards, known as The Digital Video Broadcasting (DVB-S2) transmission system employs a LDPC coding technique as a channel coding scheme.

Recently, an important issue is DVB-S2 system for mobility. The Fast Internet for Fast Train Hosts (FIFTH) project in Europe aims at providing digital TV and internet services to passengers of high-speed trains based on DVB-S. To take into account the possibility offered by the DVB-S2 specifications, the FIFTH project decided to carry out investigation on the possibility to replace DVB-S with DVB-S2 in the FIFTH forward link. Since DVB-S2 has been defined for a fixed satellite channel, no countermeasures are present in the system architecture for the system to properly work in presence of long deep fading events. In deep fading channel, since error bursts are spreading before DVB-S2 system, additional cascaded co-decoders are needed while maintaining spectral efficiency. The channel interleaving and Reed Solomon coding technique are required. This solution will be adopted in the DVB-H standard currently under preparation, to adapt the DVB-T standard for mobile reception. Therefore, this thesis analyzes the modified DVB-S2 system to adapt DVB-H and DVB-T for mobile reception by satellite broadcasting system.

This thesis organized as follows. In section 2, several DVB specifications are analyzed. Section 3 describes DVB-S2 for mobility and Section 4 shows simulation results. Finally, section 5 gives conclusion.